Impaired right ventricular function

Impaired right Ventricular (RV) function may be caused by pulmonary hyperte nsion or myocardial ischemia. It is characterized by a dilation of the RV, which is followed by an increase of wall tension and O-2-consumption and a decrease of RV ejection fraction (RV 'dysfunction'). If a drop of arterial pressure occurs this my precipitate RV failure and shock (RV 'insufficiency '). Diagnosis of RV failure and monitoring of RV function is difficult. Som etimes, even a severe impairment of RV function goes undetected or is misin terpreted. Patients in the operating room or on intensive care units seem t o be especially prone to RV dysfunction and failure. Since a causative ther apy often is not readily available, adequate symptomatic therapy is of utmo st importance. Four basic principles have to be considered: 1) Optimizing p reload: The failing RV requires adequate filling for preservation of stroke volume. On the other hand, overdistension of the RV may result in RV ische mia, thereby further deteriorating RV function Hence, volume loading is imp ortant, but requires continuous monitoring. 2) Maintenance of aortic pressu re: Vasopressors are indicated if there is a critical drop of coronary perf usion pressure. Norepinephrine presently is the drug of choice for this pur pose. 3) Reduction of RV/afterload: Whereas intravenous vasodilators are li mited in their efficacy in dilating pulmonary vessels due to systemic side effects, inhaled vasodilators result in selective pulmonary vasodilation an d may improve RV function. 4) increase of RV/contractility: In RV failure a nd shock, norepinephrine and epinephrine are the drugs of choice. Inodilato rs are well suited for reducing pulmonary vascular resistance due to their positive inotropic and vasodilating effects. Since systemic vasodilation ma y occur, these drugs must only be used in hemodynamically stable patients.